Apparatus for expanding the worksurface of a vise-like workholding apparatus

ABSTRACT

A shield for use in connection with a workholding apparatus that has a base having a longitudinal slot and at least two jaw members operably supported on the base for selectively clamping a workpiece therebetween. The shield comprises a plate member adapted to be removably received on the base and configured to permit at least one jaw member to move relative thereto. The plate member may be sized to provide the workholding apparatus with a worksurface that is wider than the base, the plate member having an opening to permit movement of the jaw members such that it is completely covered by the cooperation of the jaw members and the plate to prevent debris from entering the longitudinal slot of the base. Alternately, the opening is provided with grooves for slidably guiding a telescoping cover plate which is attached to movable support members and is cooperated with the cover plate to completely cover the longitudinal slot during the clamping operation.

This is a continuation-in-part application of U.S. patent applicationSer. No. 08/192,193, filed Feb. 4, 1994, now U.S. Pat. No. 5,442,844,which is a continuation of U.S. patent application Ser. No. 07/998,805,filed Dec. 30, 1992, now abandoned, which was a divisional applicationof U.S. patent application Ser. No. 07/955,361, filed Oct. 1, 1992, nowabandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to workholding apparatuses and, moreparticularly, is directed to apparatuses for expanding the worksurfaceof a single precision workholding vise or a collection of precisionworkholding vises arranged on a common support member.

2. Description of the Invention Background

During the machining of a "workpiece" on a machine tool apparatus suchas a milling machine or the like, single or multiple workpieces aretypically held in place by a precision vise or clamping member ("avise-like workholder") that is attached to the machine. Exemplaryvise-like workholders that are adapted to hold a single workpiece aredisclosed in U.S. Pat. No. 4,928,937 to Bernstein, U.S. Pat. No.4,898,371 to Mills et al., U.S. Pat. No. 4,569,509 to Good, and U.S.Pat. No. 4,098,500 to Lenz. As can be gleaned from review of thosepatents, such vise-like workholders are adapted to clamp a workpiecebetween opposing jaw members operably supported on a base. Typically,one jaw member is fixed and the other jaw member is movable relative tothe fixed jaw by means of a screw member housed within the base. As themovable jaw member is moved towards the fixed jaw member, the workpieceis clamped therebetween.

Other vise-like workholders are capable of holding two or moreworkpieces in side-by-side orientations. Examples of such "two-station"workholders are disclosed in U.S. Pat. No. 5,098,073 to Lenz, U.S. Pat.No. 5,094,436 to Stephan, III, U.S. Pat. No. 5,022,636 to Swann, U.S.Pat. No. 4,934,674 to Bernstein, and U.S. Pat. No. 4,529,183 to Krasonet al. Such workholders typically comprise a base that has a central jawfixed thereto. Two outer jaws are operably supported on the base and canbe selectively positioned relative to the fixed central jaw by a visescrew that is operably received in a longitudinal cavity provided in thebase.

The workpiece or workpieces are supported on the workholder bases ofeach of the above-mentioned workholders and are secured in position byat least two jaw members. The portion of the base upon which theworkpiece is supported is known as the "worksurface" of the workholder.In many workpiece machining operations, it is desirable to use aworkholder that is equipped with jaws and a worksurface that are atleast as wide as the workpiece being machined to ensure that theworkpiece is adequately supported during the machining operation.Moreover, with the ever increasing use of computer numericallycontrolled ("CNC") machine tool apparatuses, it is desirable to presentas many workpieces as possible to the machining apparatus at a singletime to reduce the amount of machine set-up and tool-change time. Thus,it is desirable to secure as many workpieces as practical between eachpair of workholding jaws.

However, because the width of the worksurface and the jaws of theabove-mentioned workholding vises cannot be "expanded" to accommodatewider workpieces or pluralities of workpieces, the user is forced toinventory a number of various sized workholders. Such workholders maytypically cost several hundred dollars and, thus, the average machineowner cannot afford to maintain an extensive inventory of suchworkholding devices.

The above-mentioned problem has been somewhat addressed in U.S. Pat. No.4,928,937 to Bernstein which discloses an arrangement of a plurality ofworkholders in an abutting, side-by-side relationship. Again, however,because the bases and jaw members of such workholding apparatuses cannotbe expanded, numerous workholders must be used to accommodate wide ornumerous workpieces.

U.S. Pat. No. 2,699,708 to Fotsch also discloses a solution to theabove-mentioned problem by providing a machine tool table that has aplurality of T-slots provided therein that are adapted to slidablyreceive a corresponding number of clamping assemblies. While thatarrangement enables a variety of different sizes of workpieces to beclamped in a desired position on the machine tool table, the clampingassemblies cannot be used on other machining apparatuses that are notequipped with a slotted table. Similarly, U.S. Pat. No. 4,898,371discloses the use of several workholder bases placed side-by-side with acommon "long" jaw blank placed therebetween for clamping longworkpieces.

All of the above-mentioned workholding apparatuses have furtherdisadvantages. In particular, during the machining of a workpiece, amachine tool is operably advanced into contact with the workpiece toremove a predetermined amount of material therefrom. As the machine toolcontacts the workpiece, such removed bits and pieces of material,commonly referred to as "chips", collect on the workholder(s) and oftenbecome trapped in exposed slots and openings therein. If those chips arenot cleaned from the workholder(s) prior to clamping the nextworkpiece(s), such chips can become jammed in various moving parts ofthe workholder(s) and possibly damage those workholder components. Thus,to prevent excessive wear and damage of the workholder components, theworkholder(s) must be carefully cleaned and often completelydisassembled to remove any chips, dirt or debris trapped therein. All ofthe aforementioned workholders have an exposed longitudinal slot that isnotorious for collecting chips and other dirt and debris therein.Similarly, the T-slots in the work table of U.S. Pat. No. 2,699,708 mustbe carefully cleaned before the clamping assemblies are slidablyinserted therein to permit precise location of the clamping assembliesand to avoid possible damage to those assemblies.

Workholding apparatuses have been designed such that the inner-workingsof such apparatuses are substantially enclosed to retard the collectionof chips and debris therein. For example, the screw member of the visedisclosed in U.S. Pat. No. 1,385,088 to Mellor is substantiallyprotected from dirt and chips by being enclosed in the vise base. Inthis workholder design, the movable jaw support member or "nut" isadapted to be slidably positioned on the base by the screw member.However, the surface of the base upon which the support member slides isexposed. Thus, chips can accumulate on that surface and, ultimately,hamper the movement of the jaw support member on the base.

The problem of chip accumulation in the longitudinal slot of a vise-likeworkholder base has been somewhat addressed in European PatentApplication Publication No. 0 526 432 A1, which was filed on Jul. 7,1992 by CUTER S.p.A of Brescia, Italy. The workholder disclosed in thatreference has a base that has a fixed jaw and a movable jaw. The basehas a longitudinal slot or "groove" that extends its entire length forreceiving a mobile jaw carriage and screw assembly. A series of notchesare also provided along portions of the base adjacent to both sides ofthe groove for engaging a flanged portion of the screw assembly. Toretard the infiltration of chips into the groove during machining,interconnected nylon blocks are placed in the groove. However, suchblocks can be inadvertently separated from the base and lost during theinstallation and storage of the workholder. Also, such block assembliesdo not prevent chips from collecting in the notches that are adjacent tothe longitudinal slot. This patent also teaches the end-to-endattachment of the vise bases to create an elongated workholding member.However, that workholder configuration also has similar chipinfiltration problems.

Another workholding apparatus that addresses the aforementioned chipinfiltration problem is manufactured by Chick Machine Tool, Inc. of 500Keystone Drive, Warrendale, Pa. 15086 under the trademarks "Bi-Lok","Qwik-Lok", and "Multi-Lok". In that workholding device, a series ofthree overlapping movable cover plates are movably supported in opposinglongitudinal grooves that are provided in the base on each side of thelongitudinal groove therein. In particular, a "central" cover plate ismovably supported in the grooves and movably attached to the movable jawsupport members such that it always covers the otherwise exposed portionof the longitudinal slot extending between the movable support members.A second plate member is attached to one of the movable support membersand is arranged to overlap the point of attachment wherein the centerplate is movably attached to that movable support member. A third platemember is attached to the other movable support member and is arrangedto overlap the point of attachment wherein the center plate is attachedto that movable support member. Such overlapping arrangement of coverplates trapped within the base serves to completely cover the slot thatextends between the movable jaw members. Although such workholder designeffectively prevents chips from entering the workholder slot, it hassome disadvantages. In particular, because the cover plates arecaptivated in opposed grooves provided in the workholder base andbecause the jaw members are movably supported on the top surface of thebase, gaps are created between the cover plates and the jaw members.Such gaps are susceptible to the accumulation of chips therein whichcould hamper the positioning of jaw members on the base. Moreover, thetime and tooling required to machine the opposing grooves in the basemember increase the costs associated with manufacturing the workholder.

Also, those workholders that have clamping assemblies slidably receivedin a longitudinal slot provided in the base, are susceptible of havingsuch clamping assemblies inadvertently advanced out of the base andpossibly damaged. To prevent such possible damage, stops are typicallyprovided to restrict the travel of the clamping assemblies. Those stops,however, must be removed each time the workholder is cleaned or servicedand, thus, increase the amount of time required to clean the chips thataccumulate within the slot.

In view of the foregoing, there is a need for an apparatus that can beused in connection with vise-like workholders to expand the worksurfacesthereof.

There is another need for apparatuses that can be used in connectionwith multiple vise-like workholders to create a substantially continuousplanar worksurface therebetween.

There is still another need for apparatus that can be used with avise-like workholders that has the abovementioned attributes and alsoserves to protect the workholder's inner-workings and base member fromchips and debris created during the machining process without hamperingthe workholder's operation.

There is a further need for apparatus that can be used in connectionwith vise-like workholders that can limit the travel of the workholder'sclamping assembly without increasing the amount of time required todisassemble and clean the workholder.

SUMMARY OF THE INVENTION

In accordance with a particular preferred form of the present invention,there is provided a shield for use in connection with a workholder thathas a base and at least two jaw members operably supported thereon. Theshield comprises a plate member that is removably received on the basebetween the jaw members and the base and is configured to permit atleast one jaw member to move relative thereto. The plate member has asecond width that is wider than the first width of the base to providethe workholder with a worksurface that is wider than the workholder'sbase.

In another embodiment, a shield is provided for use in connection with aworkholder that has a base that has a longitudinal axis and alongitudinal cavity having a slot extending along the longitudinal axis.A central jaw member is attached to the base and first and secondmovable support members are each supported on the base for longitudinalmovement along the slot toward and away from the center jaw member. Afirst jaw member is attached to the first support member and a secondjaw member is attached to the second support member. The shield, in apreferred form, comprises a plate member that is removably received onthe base between the center, first, and second jaw members and the base.The plate member has a first opening therein for receiving the firstsupport member therein and a second opening for receiving the secondsupport member therein. The plate member is wider than the base andcooperates with the first and second jaw members to substantiallycompletely cover the slot to prevent debris from entering therein.

In yet another embodiment, a workholding system is disclosed. In apreferred form, the workholding system comprises a support member and atleast two workholders that each have a base and at least two jaw membersoperably supported thereon. Each base has a plate member removablyreceived thereon between the jaw members and the base. Each plate memberhas two longitudinal edges and is configured to permit at least onecorresponding jaw member to move relative thereto. Each plate member iswider than the base upon which it is received. Attachment members areprovided for attaching the bases of the workholders to the supportmember such that at least one longitudinal edge of each plate member isin abutting relationship with at least one longitudinal edge of anotherplate member to create a substantially continuous planar worksurfacetherebetween.

In another embodiment of the present invention, a shield is provided foruse in connection with a workholder that has a base that has alongitudinal axis with longitudinal cavity having a slot extending alongthe longitudinal axis. The workholder further has a center jaw memberthat is attached to the base and first and second movable supportmembers that are supported on the base for longitudinal movement alongthe slot toward and away from the center jaw member. In addition, theworkholder has a first jaw member that is attached to the first movablesupport member and a second jaw member that is attached to the secondmovable support member. The shield, in a preferred form, comprises aplate member that is removably received on the base between the center,first and second jaw members and the base. The plate member has a slottherein that is adapted to receive the first and second movable supportmembers therein such that the first and second movable support memberscan be selectively advanced along the slot toward and away from thecenter jaw member. A longitudinally telescoping cover plate assembly isslidably attached to the plate member and is arranged to span theopening in the plate member and be selectively coextensive therewith.The cover plate assembly has portions attached to the first and secondmovable support members for travel therewith such that the cover plateassembly, in cooperation with the first and second jaw members,substantially completely covers the slot in the base.

Thus, it is an object of the present invention to provide a relativelyinexpensive apparatus that can be used in connection with a vise-likeworkholder for expanding the workholder's worksurface.

It is another object of the present invention to provide apparatusesthat can be used in connection with a plurality of vise-like workholdersfor creating a substantially continuous planar worksurface therebetween.

Yet another object of the present invention is to provide an apparatusthat can be used in connection with vise-like workholders to protect theworkholder's inner workings and base member from chips and debriscreated during the machining process without hampering the workholder'soperation.

Further, it is an object of the present invention to provide a means forlimiting the longitudinal movement of the movable clamping members of aprecision vise-like workholder to eliminate the need for auxiliary screwand to facilitate cleaning of the workholder by allowing for easydisassembly.

Accordingly, the present invention provides solutions to the problemsdiscussed above. In particular, the present shield member can beremovably attached to the base of a vise-like workholder to expand theworksurface thereof. The present shield member is much less costly tomanufacture and easier to store than the workholders themselves. Thus,it is much more economically feasible for the machine user to store anumber of the present shield members of various widths to provide theowner with the capability of machining various sizes and numbers ofworkpieces on a "standard" sized workholder. In addition, the subjectshield member can be used with a plurality of workholders arranged tocreate a substantially continuous planar worksurface therebetween. Suchworkholding arrangement permits a relatively small number of "standard"workholders to be used to create a vise-like workholding system capableof holding numerous or relatively large, odd shaped workpieces in aprecise location relative to a machine tool apparatus. The subjectshield member also serves to prevent the infiltration of chips into theworkholder base while protecting the base and the inner-workings of theworkholder against accidental damage. Therefore, the subject shieldmember addresses a number of problems commonly encountered when usingother known workholders. However, these and other details, objects andadvantages will become further apparent as the following detaileddescription of the present preferred embodiment thereof proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, there is shown present preferredembodiments of the invention wherein like reference numerals areemployed to designate like parts and wherein:

FIG. 1 is a plan view of a preferred shield member of the presentinvention installed on a vise-like workholder;

FIG. 2 is an end elevational view of the shield member and vise-likeworkholder assembly depicted in FIG. 1;

FIG. 3 is a plan view of the workholder of FIGS. 1 and 2 with the shieldmember removed therefrom;

FIG. 4 is a partial cross-sectional elevational view of the workholderof FIGS. 1-3 taken along line IV--IV in FIG. 1, with some elements shownin full view for clarity;

FIG. 5 is a plan view of the workholder and shield member of FIGS. 1-4with the first and second jaw members removed therefrom for clarity;

FIG. 6 is a plan view of a preferred shield member of the presentinvention;

FIG. 7 is a perspective view of a preferred assembly of vise-likeworkholders of the present invention;

FIG. 8 is a plan view of the workholder assembly of FIG. 7;

FIG. 9 is an end elevational view of the workholder assembly of FIGS. 7and 8;

FIG. 10 is an end elevational view of a workholder assembly having asingle shield member of the present invention thereon and having apreferred endcap attached thereto;

FIG. 11 is a side elevational view of another preferred workholderassembly of the present invention attached to a support plate;

FIG. 12 is a plan view of the workholder assembly of FIG. 11;

FIG. 13 is a cross-sectional elevational view of the workholder assemblydepicted in FIGS. 11 and 12 taken along line XIII--XIII in FIG. 12 withsome of the elements thereof shown in full view for clarity;

FIG. 14 is a side elevational view of another workholder assembly of thepresent invention;

FIG. 14A is a plan view of another workholder assembly of the presentinvention;

FIG. 15 is a side elevational view of yet another workholder assembly ofthe present invention;

FIG. 16 is a plan view of another preferred shield member of the presentinvention;

FIG. 17 is a partial cross-sectional assembly view of the cover platesand shield member depicted in FIG. 16 with the cover plates shown infull view for clarity; and

FIG. 18 is a partial cross-sectional elevational view of the shieldmember of FIGS. 16 and 17 removably received on the base of aworkholder.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings for the purposes of illustrating presentpreferred embodiments of the invention only and not for purposes oflimiting the same, FIGS. 1 and 2 illustrate a preferred shield member 10of the present invention received on the base 22 of a vise-likeworkholder 20. The basic structure of the workholder 20 is similar tothe workholding apparatus described in my U.S. Pat. No. 5,022,636,issued Jun. 11, 1991, entitled "Workholding Apparatus", the disclosureof which is herein incorporated by reference. As such, in the present"Detailed Description Of Preferred Embodiments", the basic structure ofthe workholder 20 will be described in general terms, it beingunderstood that the particular details of the workholder 20construction, with the exception of those features which are describedhereinbelow forming these embodiments of the present invention, may begleaned from a review of that patent. In addition, the skilled artisanwill readily appreciate that the workholders described herein areprovided as examples of the types of workholders with which the shieldmember embodiments of the present invention may be used. As such, theparticular construction of the workholders described herein should notbe construed to limit the breadth of protection afforded to the presentshield member embodiments described herein and recited in the appendedclaims.

The vise-like workholder 20 generally comprises a base member 22 whichis an elongated metallic structure typically fabricated from a highstrength aluminum material. As can be seen from reference to FIGS. 2 and3, a cavity 27 is machined along the longitudinal axis "A--A" of thebase member 22 and defines a longitudinal slot 24 having twolongitudinally extending side rail members 26. In addition, afree-floating clamping assembly, generally designated as 30, is providedfor movement within the cavity 27 in the base member 22. The clampingassembly 30 includes a first movable support member 32 and a secondmovable support member 34 which are each slidably received within thecavity 27. As shown in FIG. 4, a first jaw member 36 is preferablyremovably attached to the first movable support member 32 and a secondjaw member 38 is preferably removably attached to the second movablesupport member 34. The jaw members (36, 38) may be similar to thoseworkholding jaw portions disclosed in U.S. Pat. No. 5,025,427 entitled"Quick Change Head For Precision Machine Vise" the disclosure of whichis also herein incorporated by reference.

The clamping assembly 30 also includes a screw shaft 40 that is receivedwithin the cavity 27 in the base member 22. One end of the screw shaft40 is provided with threads 42 which are intended to engage a threadedbore 33 within the first movable support member 32. See FIG. 4. Inaddition, the screw shaft 40 includes means (not shown) for engaging anddisplacing the secondary movable support member 34. The screw shaft 40passes through the second movable support member 34 while the other endof the screw shaft 40 has a socket 44 .therein for receiving rotaryselectively providing rotary motion to the screw shaft 40.

A "first" center jaw member 50 is also attached to the base 22 betweenthe first and second movable support members (32, 34) preferably bycapscrews 51. In particular, threaded bores (not shown) are provided inthe rails 26 of base 22 for receiving the capscrews 51 therein.Preferably, bushings 53 are attached to base 22 such that one bushing 53is coaxial with a corresponding threaded bore adapted to receive acapscrew 51. The first center jaw member 50 may preferably be attachedto base 22 by the method and apparatus taught in my U.S. patentapplication Ser. No. 07/955,361, a parent application hereto or by theapparatus and method disclosed in a co-pending U.S. patent applicationSer. No. 08/300,375, entitled "Apparatus For Positioning An Element On ASurface," filed on Sep. 2, 1994, and owned by the owner of the presentapplication, the disclosure of which is also herein incorporated byreference. However, other precise fastening methods may also be used toattach the first central jaw member 50 to the base 22.

As can be seen in FIG. 4, the first center jaw member 50 is arranged onbase 22 such that the first and second movable support members (32, 34)may move toward and away from the center jaw member 50 to cause, forexample, workpieces 52 and 54 to be clamped between the first center jawmember 50 and first and second jaw members (36, 38). For example, whenthe screw shaft 40 is rotated, the first movable support member 32 ismoved relative to the first center jaw member 50, thereby causing thefirst jaw member 36 to move toward the first center jaw member 50 toclamp a first workpiece 52 therebetween. In addition, the rotation ofthe screw shaft 40 and its movement relative to the first movablesupport member 32 causes the second movable support member 34 to movetoward the first center jaw member 50 to engage and restrain a secondworkpiece 54 therebetween.

As can be seen in FIG. 2, the rails 26 of the workholder base 22 definea planar worksurface (that has a slot 24 extending the length thereof),generally designated as 28. As can be further seen in FIG. 2, theworksurface 28 has a "first" width generally represented by distance"B". The worksurface 28 also has "first" length, generally representedby distance "C".

A preferred shield member 10 of the present invention is shown in FIGS.5 and 6. The shield member 10 comprises a plate member 12 that ispreferably fabricated from high strength tool steel; however, othermaterials may also be successfully used. As can be seen from FIG. 6, theplate member 12 preferably has a "second" length "D" and a "second"width "E". Preferably, second length "D" is substantially equivalent tofirst length "C"; however, in those applications wherein it isadvantageous to elongate the worksurface 28 of the workholder 20, theskilled artisan will appreciate from a further reading of the presentDetailed Description Of Preferred Embodiments, that the worksurface 28can be effectively elongated to a predetermined size by providing theplate member 12 with a second length "D" that is greater than the firstlength "C".

The plate member 12 is preferably designed to be removably received onthe base 22 and is sized such that its second width "E" is wider thanthe first width "B" of the worksurface 28 of the base 22. It will alsobe appreciated that the width "E" of the plate member 12 can be made toform a worksurface of any predetermined width. To facilitate themounting of the plate member 12 on the base 22, the plate member isprovided with two longitudinal openings 14 and 16 adapted to movablyreceive therein the first and second movable support members (32, 34).More specifically, as can be seen in FIG. 5, the first opening 14 isadapted to movably receive the first movable support member 32 and thesecond opening 16 is sized to movably receive the second movable supportmember 34. Also, in this embodiment, the plate member 12 has bores 18therein that are adapted to receive locating bushings 53 that aremounted in the rails 26 for receiving cap screws 51 therein to locateand removably attach the center jaw 50 to the base 22. The skilledartisan will appreciate that, for those vise-like workholders than onlyhave one movable support member and a single fixed jaw, the plate member12 is preferably fabricated with a single opening adapted to receive thesingular movable support member therein.

In this embodiment, the first and second openings (14, 16) are sizedsuch that the first and second movable support members (32, 34),respectively, may freely move therein along the slot 24. In addition,openings (14, 16) are preferably sized to provide the first and secondmovable support members (32, 34), respectively, with predeterminedranges of axial travel along the longitudinal axis A--A of the slot 24.In a preferred embodiment, the first and second openings (14, 16) aresized relative to the size of the first and second jaw members (36, 38)such that the first and second openings (14, 16) are always covered bythe corresponding first and second jaw member (36, 38) regardless of thelongitudinal position of the primary and secondary movable slide members(32, 34) within the corresponding first and second openings (14, 16).Thus, it will be appreciated that the plate member 12, in cooperationwith the first and second jaw members (36, 38), serve to substantiallycompletely cover the slot 24 to prevent chips, dirt and other debriscreated by the machining process (collectively "foreign matter") fromentering therein. It will be further appreciated that the plate member12, by virtue of being wider than the base 22, serves to effectivelyincrease the worksurface 28 of the workholder 20. The reader will alsoappreciate that when plate member 12 is received on the base 22 as shownin FIG. 5, the plate member, by virtue of being removably retained onthe base, serves to prevent the slide assembly 30 from beingaccidentally advanced out of slot 24. Also, as shown in FIG. 1, thefirst center jaw member 50 can be made as wide as width "E" of the platemember 12. The skilled artisan will also appreciate that first andsecond jaw members (36, 38) can also be fabricated with widths thatequal width "E" or with other widths that are greater than width "B" ofbase 22. Thus, the machine operator can inventory various shield members10 and jaw members (36, 38) that are sized for supporting particularworkpieces during machining without having to inventory various sizes ofcomplete workholders.

As can also be appreciated from the foregoing, the shield member 10 ofthe present invention can be used to create a workholding system thatcomprises a plurality of workholding apparatuses that have asubstantially continuous planar worksurface extending therebetween. Moreparticularly and with reference to FIGS. 7-9, there is shown aworkholding system, generally designated as 100, that comprises asupport member 110 that has a plurality of vise-like workholders 20attached thereto such that the longitudinal axes "A--A" of theworkholders 20 are substantially parallel to each other and the platemembers 12 received thereon are arranged in abutting relationship tocreate a substantially continuous planar work surface, generallydesignated as 128, therebetween.

Preferably, the support member 110 comprises a planar support plate 112that has a plurality of bores 114 therein arranged in a predeterminedarray of orthogonally arranged rows and columns. Support or "tooling"plates of this type are known in the art and, therefore, will not bediscussed in great detail herein. As can be seen in FIG. 4, each bore114 preferably has a lower threaded portion 116 and a locating bushing118 pressed therein that is fabricated from hardened tool steel. Thebase 22 of each workholder 20 is provided with a pair of removablyattachable locating pins (23, 25) such as those manufactured by ChickMachine Tool, Inc., that extend from the bottom surface thereof and arecapable of being inserted into any of two corresponding bushings 118 inthe support plate 112 to precisely locate the workholder base 22 on thesupport plate 112. Both of the locating pins (23, 25) may be round orone pin may be provided with a "diamond" shape in a manner known in theart. It will be appreciated that when the locating pins (23, 25) engagelocating bushings 118 in corresponding bores 114 on plate 112, the base22 of the workholder 20 will be precisely located on the plate 112 in apredetermined position.

In this embodiment, the base 22 of each workholder 20 is attached to theplate 112 by cap screws 31 that extend through holes 29 in the base tothreadedly engage the threaded portion 116 of corresponding bores 114.See FIG. 4. The skilled artisan will appreciate that each base 22 of aworkholder 20 can be attached to a support plate or other member in aprecise relationship to one another by a myriad of other known locatingand fastening methods and apparatus without departing from the spiritand scope of the present invention. For example, the apparatus disclosedin the copending U.S. patent application entitled "Apparatus forPositioning An Element On A Surface", Ser. No. 08/300,375 that wasmentioned above and herein incorporated by reference may also besuccessfully used to attached the bases 22 of the workholders 20 to asupport plate 112 in predetermined orientations. Also, as can be seen inFIGS. 7 and 9, the outer perimeter of plate 112 preferably has aperimetrical groove 113 therein for receiving commercially availableclamping members for attaching the plate 112 to a machine toolapparatus. However, other known fastening methods may also be used toattach the support plate 112 to a machine tool apparatus in apredetermined location.

By way of example, FIGS. 7-9 illustrate a workholding system 100 that iscomprised of 3 workholders 20 that are each equipped with a shieldmember 10 of the present invention. As can be most particularly seen inthose Figures, the workholders 20 are located and attached to thesupport plate 112 by using one of the above-described attachment methodssuch that the longitudinal axes A--A of the workholders 20 aresubstantially parallel to each other and at least one of thelongitudinal edges 13 (See FIG. 6) of each plate member 12 is inabutting relationship with at least one other longitudinal edge 13 ofanother adjacent plate member 12. It will be appreciated that thecollection of abutting plate members 12 serves to create a substantiallycontinuous and planar worksurface, generally designated as 128, betweenthe workholders 20. It will be further appreciated that the first andsecond jaw members (36, 38) of each workholder 20 may be provided invarious sizes and shapes suited to the shape of the workpiece(s) to bemachined. It will be still further appreciated that the substantiallycontinuous planar worksurface 128 also serves to prevent foreign matterfrom collecting between the adjacent workholders 20. In addition, thoseof ordinary skill in the art will appreciate that a single shield member10" may be provided to create a substantially continuous worksurfacebetween the bases. See FIG. 10. Also, to further prevent foreignmaterial from entering the space between adjacent workholders 20, endcapmembers 130 may be attached to the ends of the workholders 20 bycapscrews 132 in the manner illustrated in FIG. 10.

In other embodiments, illustrated in FIGS. 11-14, two or more workholderbases (22, 22') may be attached to a support plate 112 to create oneelongated workholder 220. FIG. 11 and 12 illustrate an elongatedworkholder 220 that comprises two workholder bases (22, 22') attached toa support plate 112 in the manner described above. As can be seen inFIG. 11, the bases (22, 22') are attached to the support plate 112 suchthat they are in abutting relationship and their longitudinal axes"A--A" are substantially coaxially aligned. Thus, in this embodiment,the slots (24, 24') in each base (22, 22') combine to create oneelongated continuous slot, generally designated as 224. The elongatedworkholder 220 further comprises an elongated clamping assembly 230sized to be received in the slot 224. The clamping assembly 230comprises a screw shaft 240 that has a threaded portion 242 that isintended to engage a threaded bore 233 within a first movable supportmember 232. In addition, the screw shaft 240 includes means (not shown)for engaging and displacing a second movable support member 234. Thescrew shaft 240 passes through the second movable support member 234while the other end of the screw shaft 240 preferably provides areceptacle 244 for receiving rotary motion which is selectively providedto the screw shaft 240.

A center fixed "first" jaw member 250 is also attached to the bases (22,22') by four capscrews 251 between the first and second movable supportmembers (232, 234) which are like first and second movable supportmembers 32 and 34. When the screw shaft 240 is rotated, the firstmovable support member 232 is moved relative to the center jaw member250, thereby causing the first jaw member 236 (like jaw member 36) tomove toward the first jaw member 250 to clamp a first workpiece 252therebetween. In addition, the rotation of the screw shaft 240 and itsmovement relative to the first movable support member 232 causes thesecond movable support member 234 to move second jaw member 238 (likejaw member 38) toward the first jaw member 250 to engage and restrain asecond workpiece 254 therebetween.

The skilled artisan will appreciate that the jaw members (236, 238, 250)can be provided in various other configurations suited to the particularworkpieces(s) to be machined. For example, in FIG. 14, the first andsecond jaws (236, 238) each have a ledge (237, 239) formed therein thatis adapted to engage the edges of one continuous workpiece 255. In thatembodiment, the center jaw member 250 is sized such that the workpiece255 is supported thereon.

FIG. 14 further illustrates the flexibility of this embodiment of thepresent invention. As can be seen in that Figure, the center jaw 250 hasbeen omitted. The plate member 12 is fabricated without the opening 14normally provided therein for a secondary movable support member 34 andthe plate 12' is fabricated without opening 14 normally provided thereinfor a movable support member 32. Such arrangement of plates (12, 12')serves to create a substantially continuous worksurface 228 that extendsthe entire length of workholder 220. As illustrated in FIG. 15, a singleplate member 12" may be provided that is configured to be received onboth workholder bases (22, 22') to create a continuous worksurfacetherebetween. The skilled artisan will further appreciate that plates(12, 12') may be fabricated with widths that are equal to the widths ofthe corresponding bases (22, 22') or plates (12, 12') may be providedwith widths that are wider than bases (22, 22') in the manner disclosedabove. The reader will also understand that elongated workholders 220can be fabricated to any desired length by adding additional bases andproviding a correspondingly sized clamping assembly and appropriatelyconstructed shield members. In addition, the elongated workholders 220and the plates (12, 12') thereof can be fabricated and attached to acorrespondingly sized support plate 112 to create a workholding systemin the manner described hereinabove.

FIG. 14A illustrates two workholders (20, 20') that are attached to asupport plate 12 such that the longitudinal axes "A--A" thereof aresubstantially perpendicular to each other. Such Figure furtherillustrates the flexibility of the present invention.

In another embodiment of the present invention, as illustrated in FIGS.16-18, a shield member 310 that comprises a plate member 312 that issized to be removably received on the base 22 of a workholder 20 isdisclosed. In a preferred form, plate 312 has an elongated slot 314 thatoverlies slot 24 in the workholder base 22. On each longitudinal side315 of slot 314, opposing grooves 316 are provided. Slidably receivedwithin opposing grooves 316 are two overlapping cover plates (320, 330)preferably fabricated from, for example, stainless steel or springsteel. To permit cover plates (320, 330) to be slidably inserted intothe grooves 316, notches 322 are provided in sides 315 as shown in FIG.16. The reader will appreciate that cover plates (320, 330) can slidablylongitudinally telescope to cover the portion of slot 24 in the base 22that is not occupied by first and second movable support members (32,34). More particularly, cover plate 320 is preferably provided with ahook-shaped forward portion 324 that is adapted to engage a ledge 41machined in first movable support member 32. See FIG. 18. The readerwill appreciate that cover plate 330 is also preferably provided with ahook-shaped portion 334 (See FIG. 16) that is adapted to engage ledge 43formed in the second movable support member 34 (See FIG. 4) in the samemanner as depicted in FIG. 18. While this method of attaching coverplates (320, 330) to first and second movable support members (32, 34),respectively, is preferred, other attachment methods may also besuccessfully used. It will be understood, therefore, that cover plates(320, 330) are longitudinally slidably displaced within grooves 316 inplate member 312 in response to the movement of the first and secondmovable support members (32, 34) within the slot 24. It will be furtherunderstood that the cover plates (320, 330) are preferably sized suchthat they serve to cooperate with first and second jaw members (36, 38)to completely cover the slot 24 regardless of where the first and secondjaw members (36, 38) are located on the base 22. Thus, this embodimentof the present invention serves to prevent foreign material fromentering the slot 24 during the machining process. Also, as with theother shield member embodiments disclosed hereinabove, plate 312 can befabricated with a width that is wider than the width of the base 22 toeffectively increase the worksurface thereof.

Accordingly, the present invention provides solutions to theaforementioned problems associated with vise-like workholdingapparatuses. The present invention provides a relatively inexpensivemeans for expanding the worksurface of a vise-like workholder. Thepresent invention further provides a means for limiting the longitudinalmovement of the clamping members of a workholding vise while alsoaffording protection from foreign objects to the vise's base and innerworkings. In addition, the present invention provides a means forcreating a substantially continuous worksurface between a plurality oflike-constructed workholders attached to a support member. While suchadvantages are apparent from the foregoing disclosure, it will beunderstood, however, that various changes in the details, materials andarrangements of parts which have been herein described and illustratedin order to explain the nature of the invention may be made by thoseskilled in the art within the principle and scope of the invention asexpressed in the appended claims.

What is claimed is:
 1. A shield for use in connection with a workholdingapparatus for clamping a workpiece, said apparatus has a base having alongitudinal axis and two spaced lateral sides substantially parallel tosaid longitudinal axis, said base having a maximum first overall widthtransverse to said longitudinal axis and a longitudinally extendingcavity therein, said base further having at least first and second jawmembers operably supported on the base such that one of said jaw membersis selectively movable along said longitudinal axis relative to theother of said jaw members for selectively clamping a workpiecetherebetween, the shield comprising a plate member removably received onthe base between the base and said movable jaw members, said platemember having means therein for permitting said movable jaw members tomove in a predetermined distance along the longitudinal axis relativethereto, such that, said plate member and movable jaw members completelycovering said longitudinally extending cavity during the clampingoperation, said plate member having a second width transverse to saidlongitudinal axis that is wider than the first width of the base suchthat said plate member extends beyond at least one said lateral side ofsaid base when it is received thereon.
 2. The shield of claim 1 whereinsaid longitudinally extending cavity comprises a longitudinal slotextending along the longitudinal axis, and wherein said workholdingapparatus has a fixed jaw member attached to the base and a firstmovable support member supported on the base for longitudinal movementalong the slot toward and away from the fixed jaw member and said firstjaw member attached to the first movable support member and wherein saidmeans for permitting comprises a first opening in said plate member forreceiving the first movable support member therein, said first openingbeing completely covered by said first jaw member when said first jawmember is attached to said first movable support member such that saidfirst jaw member and said plate member completely cover the slot whensaid plate member is received on said base and said first jaw isattached to said first movable support member to prevent debris fromentering therein.
 3. The shield of claim 2 wherein said first opening issized to limit the travel of the first support member to a firstpredetermined path of axial travel in the slot such that the first jawmember always covers said first opening during the clamping operation.4. The shield of claim 2 wherein the workholder further has a secondmovable support member supported on the base for longitudinal movementalong the slot toward and away from the fixed jaw member and said secondjaw member attached to the second support member and wherein said platemember further comprises a second opening therein for receiving thesecond support member therein, said second opening being completelycovered by the second jaw member such that the first and second jawmembers and said plate member completely cover the slot to preventdebris from entering therein.
 5. The shield of claim 4 wherein saidsecond opening is sized to limit the longitudinal travel of the secondsupport member to a second predetermined path of axial travel such thatthe second jaw member always covers said secondary opening during theclamping operation.
 6. A shield for use in connection with a workholdingapparatus for clamping a workpiece, said apparatus having a base, havinga longitudinal axis a top surface and two spaced lateral sidessubstantially parallel to said longitudinal axis, said base having amaximum first overall width transverse to said longitudinal axis and alongitudinal slot in said top surface extending along the longitudinalaxis, a fixed jaw member attached to the base and first and secondmovable support members each being supported on the base forlongitudinal movement along the slot toward and away from the fixed jawmember, a first jaw member attached to the first movable support memberand a second jaw member attached to the second movable support member,the shield comprising a plate member removably received on the basebetween the first and second jaw members and the base, said plate memberhaving a second width transverse to said longitudinal axis that isgreater than said first width such that said plate member extends beyondat least one said lateral side of the base when it is received thereon,said plate member having a first opening therein for receiving the firstmovable support member therein and a second opening for receiving thesecond movable support member therein, said plate member and the firstand second jaw members substantially completely covering the slot duringthe entire clamping operation when said plate member is received on saidbase and said first and second jaw members are attached to said firstand second support members, respectively.
 7. The shield of claim 6wherein said first opening is sized to limit the travel of the firstsupport member to a first predetermined path of axial travel such thatthe first jaw member always covers said first opening and wherein saidsecond opening is sized to limit the travel of the second support memberto a second predetermined path of axial travel such that the second jawmember always covers said secondary opening during the clampingoperation.
 8. A shield for use in connection with a workholdingapparatus for clamping a workpiece, said apparatus comprising having abase having a longitudinal axis and a first longitudinal slot extendingalong the longitudinal axis, a center jaw member attached to the baseand first and second movable support members each being supported on thebase for longitudinal movement along the slot toward and away from thecenter jaw member, a first jaw member attached to the first supportmember and a second jaw member attached to the second support member,the shield comprising:a plate member removably received on the basebetween the first and second jaw members and the base, said plate memberhaving a longitudinal opening therein for receiving the first and secondsupport members therein such that the first and second support memberscan be selectively advanced toward and away from said center jaw member;and a longitudinally telescoping cover plate assembly slidably receivedin a guiding means of said removable plate member, said cover plateassembly spanning said longitudinal opening therein and beingselectively coextensive therewith, said telescoping cover plate assemblyattached to said first and second movable support members for traveltherewith such that said cover plate assembly, in cooperation with thefirst and second jaw members, substantially completely covers the slotin the base during the clamping operation.
 9. The shield of claim 8wherein said cover plate assembly comprises:a first cover plate slidablyreceived in said guiding means of said removable plate member andspanning a portion of said longitudinal opening in said removable platemember, said first cover plate configured to engage the first movablesupport member for travel therewith; and a second cover plate slidablyreceived in said guiding means of said removeable plate member inoverlapping relationship with said first cover plate member and spanninga portion of said longitudinal opening therein, said second cover platemember being configured to engage the second movable support member fortravel therewith.
 10. The shield of claim 9 wherein said guiding meansfurther comprising groove means in said plate member, said groove meansbeing adjacent to said longitudinal opening for slidably receiving saidfirst and second cover plate members therein.
 11. The shield of claim 9wherein said first cover plate member has a first hook-shaped portionthereon adapted to engage a first engagement portion on the firstmovable support member to attach said first cover plate member to thefirst movable member and wherein said second cover plate member has asecond hook-shaped portion thereon adapted to engage a second engagementportion on the second movable support member to attach said second coverplate member to the secondary movable support member.
 12. The shield ofclaim 8 wherein the base of the workholder has a first overall width andsaid plate member has a second width that is wider than said firstwidth.